Chapter 6 & 7 Overview
Define:
Somatic cell, gamete, homologous chromosome, autosome, sex chromosome, sexual
reproduction, fertilization, diploid, haploid, meiosis, gametogenesis, sperm, egg, polar
bodies, trait, genetics, purebred, cross, law of segregation, gene, allele, homozygous,
heterozygous, genome, genotype, phenotype, dominant, recessive, punnett square,
monohybrid cross, law of independent assortment, probability, crossing over, genetic
linkage, Carrier, sex linked gene, X chromosome inactivation, incomplete dominance,
codominance, polygenic trait, linkage map, pedigree, karyotype
Answer:
(6.1) Key Concept: Gametes have half the number of chromosomes that body cells
have.
1. What are the two major groups of cell types in the human body? __________________
________________________________________________________________________
2. Where are gametes located? _______________________________________________
3. How many chromosomes are found in a typical human body cell? ________________
4. What is the sex of a person with two X chromosomes?____________
Two Y chromosomes? ___________
MAIN IDEA: Body cells are diploid; gametes are haploid
5. What happens to the nuclei of the egg and sperm during fertilization? ______________
________________________________________________________________________
6. What type of cells are haploid? ____________________________________________
7. What is the haploid chromosome number in humans? _________________________
8. Complete the following table;
Mitosis
Meiosis
Makes
Makes diploid cells
Makes genetically different (unique) cells
Makes genetically
Happens throughout your lifetime
Happens
Involved in sexual reproduction
9. Draw a picture of a homologous chromosomes
(6.2) KEY CONCEPT: During meiosis, diploid cells undergo two cell divisions that
result in haploid cells. Cells go through two rounds of division in meiosis.\
10. After a chromosome is replicated, each half is called a ____________________.
11. Sketch the phases of meiosis I and II label the name of each phase (use fig. 6.5 to help
you)
12. What does a sperm cell contribute to an embryo? ______________________
13. What does an egg cell contribute to an embryo? _______________________
(6.3) KEY CONCEPT: Mendel’s research showed that traits are inherited as
discrete units.
14. Describe the study of Genetics? ___________________________________________
________________________________________________________________________
15. How did Mendel’s views on inheritance differ from the views of many scientists of
his time?________________________________________________________________
________________________________________________________________________
16. Why did Mendel use pea plants? _________________________________________
17. Describe Mendel’s Law of Segregation_____________________________________
________________________________________________________________________
(6.4) Key concept: Genes encode proteins that produce a diverse range of traits.
18. What is the relationship between genes and proteins? __________________________
________________________________________________________________________
19. What is an allele? ______________________________________________________
20. What does phenotype mean? ____________________________________________
Give an example of a phenotypic characteristic ___________________________
21. What does genotype mean? _____________________________________________
Give an example of a genotypic characteristic____________________________
22. How are alleles represented on paper? ___________________________________
A capital letter represents a __________________allele
A lowercase letter represents a _______________allele
23. Complete the table:
Genotype
Homozygous
dominant
Phenotype
Alleles
Recessive
Tt
24. What is the alternative form of a gene?______________________________
25. What is the opposite of heterozygous? ______________________________
26. What is the opposite of recessive? _________________________________
(6.5) KEY CONCEPT: The inheritance of traits follows the rules of probability
27. Draw a picture of a Punnett square & LABEL the parts
28. Draw a punnet square for a homozygous recessive parent (ff) who breeds with a
Heterozygous parent (Ff).
(6.6) KEY CONCEPT; Independent assortment and crossing over during meiosis
result in genetic diversity
29. What are two ways that sexual reproduction helps create and maintain genetic
diversity? ______________________________________________________________
_______________________________________________________________________
30. Which does sexual reproduction create; New alleles OR new combinations of alleles?
_______________________________________________________________________
31. How is the production of unique genetic combinations an advantage to organisms of a
species? _______________________________________________________________
32. Draw a picture of Crossing over. Use figure 6.20 on page 190 to help you.
33. Summarize Mendel’s three basic laws;
a. ________________________________________________________________
________________________________________________________________________
b. ________________________________________________________________
________________________________________________________________________
c. ________________________________________________________________
________________________________________________________________________
(7.1) KEY CONCEPT: The chromosomes on which genes are located can affect the
expression of traits.
34. What are sex chromosomes? ____________________________________________
35. What are autosomes? __________________________________________________
36. How is a carrier different from a person who has a genetic disorder? _____________
_______________________________________________________________________
37. How are sex-linked genes expressed differently in the phenotypes of males and
females? _______________________________________________________________
______________________________________________________________________
38. Describe three factors that may affect phenotype
a. Incomplete dominance_____________________________________________
_______________________________________________________________________
Give an example of incomplete dominance_________________________
________________________________________________________________________
b. Co-dominance____________________________________________________
________________________________________________________________________
Give an example of Co-dominance________________________________
________________________________________________________________________
c. Polygenic Trait___________________________________________________
_______________________________________________________________________
Give an example of polygenic traits______________________________
(7.4) KEY CONCEPT: A combination of methods is used to study human genetics
39. How does genetic inheritance follow similar patterns in all sexually reproducing
organisms? __________________________________________________________
40. Who can be carriers of autosomal disorders? ______________________________
_____________________________________________________________________
41. Why are some sex-linked diseases only expressed in males? ____________________
________________________________________________________________________
42. What is a pedigree? ________________________________________________
43. What is a Karyotype? _________________________________________________